facebook 登录回调不调用可能原因

就本人遇到的情况而言，有以下两种

1. FacebookDisplayName 填写错误

2. 使用了iOS13中的UIScene，处理URL Schemes时，需到SceneDelegate.swift文件处理

func scene(_ scene: UIScene, openURLContexts URLContexts: Set<UIOpenURLContext>) {
if let context = URLContexts.first {
        var options = [UIApplication.OpenURLOptionsKey: Any]()
        options[.sourceApplication] = context.options.sourceApplication
        options[.annotation] = context.options.annotation
        options[.openInPlace] = context.options.openInPlace
        ApplicationDelegate.shared.application(UIApplication.shared, open: context.url, options:options)
    }
}